Wednesday, 19 November 2008

A taste of psychology

This isn't how it's supposed to be done, you deserve something a bit lighter, with pictures, about some trivial thing that's happened to me. But, hey ho, you get another heavy university lecture...

The Psychology lecture was interesting the other day. We were looking at stress and its effects on eating. There was quite a lot of stuff that you'd expect, and the usual equivocal evidence that seems endemic to psychology, given that we can't open up the brain and see for ourselves what's going on. It's frustrating to have to rely on what people say.

Yes, most people tend to eat more when they are stressed, and some tend to eat more when their mood is good, but some will eat less when they are depressed, and I can certainly eat less when I'm happy. So that's all four possible combinations, and anyway self-reported food intake is always horribly inaccurate, and more so when the person is depressed.

The most interesting observation was that fear and anxiety are incompatible with the physical act of eating. It isn't possible to be afraid or anxious while you are actually putting food in your mouth, chewing and swallowing. On reflection, this seems eminently true, I don't think I could eat if I were truly afraid, but the converse is more prevalent - we sometimes eat because to do so makes us less anxious, at least temporarily. Eating banishes anxiety and makes us feel better for a short while.

Another interesting proposition is the Dietary Restraint hypothesis. This suggests that if you constantly restrict your intake through conscious control of eating, then the physiological satiety signal (that is, your body rather than your conscious mind telling you when to stop eating) may become weaker or disappear. If your psychological state is disturbed by stress or emotion, then your conscious control of eating may be disrupted. In the absence of the physiological signal, you have nothing to tell you when to stop, and you carry on eating beyond what is necessary for satiety. Sounds good - but that's as far as they've got in the research, there's nothing yet to suggest what to do about it.

The psychology teaching in this module is based entirely on research evidence and theories about eating: the influence of stress, gender differences, social inequality. It's all been very interesting, and I know it can work to change eating behaviour, plus there seems no other long-term non-invasive way (although the fat-inhibiting drugs do quite well). I was convinced before I started on this course that losing or gaining weight is a psychological issue, and nothing has changed that view so far. What you choose to put in your mouth is dictated by your brain, and nothing else. Brains are a terrible nuisance, though, and rather difficult to control.

I've seen several recent articles, however, claiming that gastric bands and bariatric surgery produce the best results for weight loss. The evidence simply isn't there for less invasive methods, because the research hasn't been done. I still have equivocal views about gastric bands, and I have nowhere near enough knowledge and experience with cognitive therapies, but surgery still seems very drastic, especially as the risks of anaesthetic are multiplied when the patient is obese, which these patients obviously are.

On a more practical note, in the Psychology module our performance is assessed entirely by coursework, with no exam. While this reduces the pressure in January, when I have four exams, I realised that I ought to be spending as much time on the coursework as I would have spent revising for an exam, and what with me being a swotty swot swot that's quite a lot. Our first coursework assignment was worth 25% of the module mark, and I didn't do as well as I would have liked. This is understandable - I've never studied psychology before and wasn't sure what was required, and the summary of our marks for the assignment showed that nobody did very well. The second coursework counts for the remaining 75%, and contains six questions. It's going OK, but I still can't tell whether I will improve my mark. It's not like learning the reaction sequence for conversion of glycogen to glucose...

2 comments:

Lola II said...

You're not a swotty swot swot!! You're a swotty swot swot specy four eyes! Love yow.

Magicchick said...

This is a really interesting post to me for obvious reasons - the link between stress, depression and food is very real to me and can be a vicious circle - stress, eat, feel bad for eating and then eat more ...